class_docstr: Independent multivariate Gaussian distribution parametrized by mean.
code: def n_inputs(self):
      n_dims = self._n_dims
      return {
          None: n_dims,
          "shared": n_dims + 1,
          "separate": n_dims * 2,
      }[self._learn_std]
  
imports: import gin
  import gym
  import numpy
  from trax import layers
  from trax.fastmath import numpy
label_desc: Use image node_id 4 for calling the Gaussian obj's underlying member method code with example usage: obj.n_inputs() and returns: dict